Method and apparatus for well operations



Feb- 11 W69 J. T. BRUMBLE, JR

METHOD AND APPARATUS FOR WELL OPERATIONS Original Filed Dec. 15, 1958 Power Supply United States Patent O 13 Claims ABSTRACT OF THE DISCLOSURE A method for perforating in a well bore which contains at least two spaced-apart pipe strings. In one of the pipe strings a directional perforator is arranged together with a source of radiation capable of transmitting radiation to a radiation detector located in another of the pipe strings to provide, upon rotation of the perforator and source of radiation, indications of the angular position of the radiation detector, and thereby the other pipe string, relative to the direction of perforation.

This application is a continuation of Ser. No. 780,517, now abandoned, entitled, Method and Apparatus for Well Operations, filed Dec. 15, 1958, by James T. Brumble, Ir.

This invention generally concerns multiple zone well operations. More particularly, the invention concerns locating pipe strings arranged in a borehole relative to the position of a well tool. In its more particular aspects, the invention concerns locating pipe strings arranged in a borehole relative to the direction of iire of a gun perforator and orienting the gun perforator to direct the fire thereof in a direction away from one or more of the pipe strings to avoid perforation thereof or toward one or more of the pipe strings to cause perforation thereof.

In multiple zone well operations, a plurality of pipe strings are arranged in a borehole which penetrates a plurality of productive intervals and production fluids from each interval are conducted independently to the earths surface through these pipe strings. In order to perforate a particular interval, a gun perforator is run in the borehole and tired in a direction to cause penetration of the formation. However, when at least two pipe strings are positioned adjacent the interval to be perforated, it is necessary to direct the re of the gun perforator to avoid striking any one of the pipe strings except the pipe string through which the gun perforator is run. Also, in well operations wherein the borehole contains a plurality of pipe strings, it may be desired to direct the re of the gun perforator to perforate one or more of the pipe strings in certain instances, as, for example, when it is necessary to establish subsurface communication between pipe strings during blowouts, workovers, etc.

These results are achieved by the present invention which provides method and apparatus for locating pipe strings in a borehole relative to the direction of iire of a gun perforator; for orienting the gun perforator; for directing the tire thereof in any desired radial diection; and for firing the gun perforator to avoid perforating a particular pipe or pipes or for perforating a particular pipe or pipes `whichever procedure is desired. Radioactivity techniques are employed for establishing location of the pipe strings, and particularly the technique of providing a radiation detector in a pipe (or pipes) to be detected and a radiation source in a different pipe.

The present invention is advantageous over prior art devices in that the use of gun guides is avoided; it permits running pipe strings in the well separately or inde- 3,426,849 Patented Feb. 11, 1969 ICC pendently or both; it avoids incorrect orientation should a pipe string rotate or slip in a clamp while being run or should a pipe string be misaligned by error; and it permits full openings through all of the pipe strings.

The above purposes and other purposes of the invention will be apparent from a description thereof taken in conjunction with the drawings wherein:

FIG. l is a cross-sectional view of the earths subsurface showing a bore hole having arranged therein two pipe strings, one of which contains a gun perforator, a focused source of radiation attached to and aligned with said perforator, and means for rotating these elements, and the other of which contains a radiation detector; also shown schematically is surface equipment for registering detected radiation and for ring the gun perforator;

FIG. 2 is a plan view of the bore'hole illustrating one manner of orientation according to the invention when the borehole contains two eccentric pipe strings; and

FIG. 3 is a similar plan view illustrating a manner of orientation when the borehole contains more than two eccentric pipe strings.

Referring more particularly to the drawings:

In FIG. l is shown a borehole 10 penetrating a subsurface productive formation 11. Two eccentric spaced-apart pipe strings 12 and 13 are cemented in borehole 10 by means of cement 14. A tool, generally designated 15, is suspended in pipe string 12 by means of a monoor multielectrically conductive cable 16. Tool 15 includes an upper section 17, which is adapted to cause rotation of tool 15 throug'h a 360 traverse, a gun perforator section 18, and a section 19 rigidly attached to and of known alignment with the perforator and adapted to supply a focused or collimated source of radiation.

Section 17 includes a cylindrical member 20\ provided with a track or groove 21 (shown here as a spiral) on the interior surface thereof made in such a manner so as to provide a 360 keyway traverse. Spring arms 22 are arranged on the exterior surface of member 20 and frictionally engage the interior wall of pipe string 12; and an extension member 23 provided with a pinion key 24, which pin or key engaes with track 21 and is adapted to ride therein. Section 18 is connected rigidly to extension member 23 and includes a plurality of gun elements 25, the lines of lire of which are directed in ixed predetermined directions relative to each other and to the focused source of radiation. Gun elements 25 may be any conventional type gun perforator such as the bullet type or the jet type. Section 19 includes a source of radiation, designated 26, and a collimating shield therefor, designated 27. Shield 27 restricts the area of bombardment to a predetermined arc, as, for example, 45. The source of radiation 26 may be fast neutrons or gamma rays. Thus, the source may be an alpha-neutron (aan), deuteron-neutron (d,n), or proton-neutron (p,n) reaction wherein the alpha particle, deuteron, or proton is accelerated by an electric field and thereby caused to interact with selected target materials in order to produce neutrons of various energizes within the connes of source 26 or the radiation may be neutrons originating from a radium-beryllium, or polonium-beryllium source. Sources of high energy gamma radiation which may be employed are: radioactive Na24, Lam, Sbm, C050, or high energy gamma rays produced by various reactions in high energy particle machines in a manner well known to the art of nuclear physics. For example, the bombardment of lithium by protons prod-uces high energy 17 mev. gamrnas. A radiation detector 30 is arranged in a housing 31 which, in turn, is suspended in pipe string 13 on an electrically conductive cable 32. Detector 30 detects slow neutrons or gamma rays or fast neutrons and for detection of this radiation, ionization chambers, Geiger-Mueller tubes, and scintillation counters may be employed. Cable 16 is connected to a surface gun switch 33 and cable 32 is connected to a radiation de tector register or recorder 34. A suitable source of power 40 adapted to supply power for firing gun elements 25, for supplying power for providing a source of radiation, if necessary, and for supplying power to detector 30 is also provided at the surface.

When it is desired to perforate an interval of formation 11, tool is lowered in pipe string 12 on cable 16 until tool 15 is in position adjacent formation 11 and housing 31 containing detector 30 is lowered in pipe string 13 by means of cable 32 until detector 30 is positioned adjacent radiation source 26. Then, member 23 is raised and lowered by means of cable 16. This causes pin 24 to travel in spiral track 21 because cylindrical member is maintained stationary by means of spring arms 22 or other restraining stop device frictionally engaging pipe string 12. Movement of pin 24, in spiral track 21 from the top of member 20 to the bottom thereof, or vice-versa, rotates gun section 18 and radiation source section 19 in at least one 360 circle. When the focused source of radiation is directed toward detector in its rotational traverse, its position is indicated by the detector recorder 34. The direction of the radiation collimating arc or the direction of the source relative to the direction of lire of gun elements 25 is predetermined and known. Once the radioactivity curve of intensity of radiation detected through a 360 traverse is obtained, pipe string 13- is positioned or located relative to the direction of fire of gun elements 25. When this position is ascertained, the line of nre of gun elements 25 may be directed away from the direction of pipe string 13 or directed toward pipe string 13, if such an operation is desired, and when properly directed the gun perforator may be fired by means of gun switch 33.

This positioning is seen more clearly in FIG. 2 wherein the arc of focused radiation is directed toward de tector 30 and in this position the direction of the lines of fire 50 of guns 25 are away from the direction of pipe string 13.

A similar situation is shown in FIG. 3 wherein an additional pipe string 36 is shown arranged in borehole 10. A detector identical to the detector nun in pipe string 13` is run in pipe string 36 and arranged or positioned adjacent detector section 19. The positions of pipe strings 13 and 36 are established by the intensity of radiation detected by the detection recorder 34 during rotation of radiation source detector 26. Once the positions of pipe strings 13 and 36 are established, tool 15 is manipulated to thereby rotate the tool until guns 25 are positioned to direct the fire thereof away from pipe strings 13 and 36, as shown in FIG. 3. When more than two pipe strings are arranged in the borehole, it may be preferable to have gun elements iire in one direction only, as shown. A similar procedure is employed when it is desired to perforate one or more of the pipe strings such as pipe string 13 or pipe string 36; however, in this instance, the line of fire is directed toward the pipe string it is desired to perforate.

Shield 27 may be formed of radiation absorbing or moderating materials such as lead, tungsten, boron, cadmium, etc., which materials are capable of absorbing or moderating the radiation emitted by source 26 in order to collimate the source in a selected direction.

If desired, a set of slips or other anchoring means may be employed instead of springs 22 for engaging the wall of pipe string 12 and maintaining cylindrical member 20 stationary.

A line or direction of iire is intended to means, as used herein, one or more directions of re.

The invention is applicable to so-called tubingless completions; that is, wells completed without setting casing. This procedure, which is illustrated in FIG. 1, includes running the desired pipe strings in the borehole and cementing the pipe strings in place. The invention is applicable also to cased wells; that is, where a casing is run in the borehole and cemented in place and the tubing strings are arranged within the casing.

Having fully described the objects, apparatus, method, and operation of my invention, I claim:

1. A method for perforating in a well bore penetrating a subsurface formation, said well bore having arranged therein :at least two eccentric, spaced-apart pipe strings comprising:

arranging in one pipe string a tool provided with a perforator having a selected direction 0f perforation, and with a source of radiation having a selected direction of bombardment relative to said perforator, and with a means capable of causing rotation of said tool;

arranging in at least one other pipe string a radiation detector;

actuating said rotating causing means to rotate said tool to determine an angular position of said detector relative to the position of said radiation source;

further rotating said tool until said direction of perforation thereof relative to said detector is in a selected direction; and

then actuating said perforator.

2. A method as recited in claim 1 including positioning the direction of perforation away from the position of said detector.

3. A method as recited in claim 1 including positioning the direction of perforation toward the position of said detector.

4. A method for perforating in a well bore having arranged therein a plurality of pipe strings comprising the steps of:

arranging in one pipe string .a rotatable tool provided with a perforator having a selected direction of perforation and provided with a collimated source of radiation having a selected direction of radiation emission fixed relative to said direction of perforation;

arranging in at least one other of said pipe strings a detector of radiation capable of detecting radiaiton emitted by said source of radiation;

rotating said tool to a selected angular position thereof as determined by radiation emitted by said source rand detected by said detector in order to orient said perforator relative to the position of said other pipe string in which said detector is arranged; and

then actuating said perforator when said tool is in said selected angular position.

5. A method as recited in claim 4 in which perforation of said pipe string in which said detector is arranged is avoided.

6. A method as recited in claim 4 in which said pipe string in which said detector is arranged is perforated.

7. A method for perforating in a wall bore having at least one pipe string arranged therein comprising the steps of:

lowering a detector of radiation in one pipe string to a depth in said well bore at Which it is desired to perforate;

lowering in said well bore external of said pipe string in which said detector of radiation is arranged to said depth a rotatable perforator having a selected direction of perforation and provided with a collimated source of radiation capable of emitting radiation detectable by said detector which is indicative of the angular position of said detector relative to said direction of perforation;

rotating said perforator to a selected angular position thereof as determined by radiation emitted by said source and detected by said detector in order to orient said perforator relative to the position of sail pipe string in which said detector is arranged; an

then actuating said perforator when said tool is in said selected angular position.

8. A method as recited in claim 7 in which perforation of said pipe string in which said detector is arranged is avoided.

9. A method as recited in claim 7 in which said pipe string in which said detector is arranged is perforated.

10. A method for perforating in a well bore employing a perforator having perforating axes lying in longitudinally extending planes wherein the angular disposition of the planes defines a zone in which perforations are not produced in one of a plurality of tubing strings in said well bore comprising the steps of:

disposing a source of radiation in one of said tubing strings with said perforator attached to said source; disposing a detector of radiation in another of said tubing strings; obtaining signals from said detector which are representative of energy transmitted between said source and detector and which are indicative of the angular position of said detector relative to the direction of perforation; simultaneously rotating said perforator and said source vdevice while obtaining said signals to derive an indication of the rotative positions of said perforator with respect to said other tubing string in which said detector is disposed in accordance with which said perforator may be selectively oriented so that said perforator when actuated avoids perforation of said other tubing string;

selectively orienting said perforator;

and then actuating said perforator.

11. Apparatus for perforating in a well ybore having arranged therein a plurality of pipe strings comprising:

a rotatable tool provided with a perforator having a selected direction of perforation and with a collimated source of radiation having a selected direction of bombardment and with means capable of causing rotation of said tool arranged in one of said pipe strings, said direction of perforation and said direction of bombardment being fixed relative to each other;

a detector of radiation arranged in at least one other of said pipe strings;

means at the surface of the earth for indicating the position of said other pipe string containing said radiation detector relative to angular positions of said rotatable tool; and

means for actuating said perforator.

12. In apparatus for perforating in selected directions in a well pipe with a perforator having a selected direction of perforation arranged in Said Well pipe, the improvement comprising:

a sleeve provided with a spiral groove on the interior surface thereof arranged in said well pipe;

a key provided on said perforator and movably arranged in said spiral groove such that when said perforator is moved vertically in said well pipe relative to said sleeve, said perforator also rotates in said well pipe; and

means connected to said sleeve for restraining movement of said sleeve relative to said well pipe, said spiral groove being formed so that suicient vertical movement of said perforator rotates said perforator through a 360 traverse whereby vertical movement of said perforator permits orienting the direction of perforation in any selected direction in said 360 traverse.

13. An apparatus for perforating in a well bore in which there are at least two eccentric spaced-apart pipe strings comprising:

a perforator having a selected radial direction of perforation arranged in one of said pipe strings;

a source of radiation having a selected radial arc of bombardment connected to said perforator, the direction of radiation bombardment being in a selected direction and fixed relative to the direction of perfoi-ation of said perforator;

means engaged with said perforator and said radiation source for rotating said perforator and radiation source at least one complete revolution to permit positioning the directions of perforation and radiation bombardment in selected radial directions;

means arranged in at least one of said other pipe strings for detecting radiation emitted by said source;

means for transmitting to and recording at the surface indications representative of said detected radiation whereby the direction of said other pipe string relative to the direction of perforation may be determined; and

means for actuating said perforator to perforate whereby when the direction of said other lpipe string relative to the direction of perforation has been determined, the perforator may be rotated to direct the direction of perforation thereof in a selected direction.

References Cited UNITED STATES PATENTS DAVID H. BROWN, Primary Examiner.

U.S. Cl. X.R. 

